1. Field of the Invention
The invention relates to a die, a tool set, and a press-forming method.
2. Description of the Related Art
Technology related to movable bodies such as vehicles is becoming more and more electronically oriented. As a result, a variety of electronic components are currently being installed in vehicles. For example, some vehicles are equipped with distance measuring equipment referred to as sonar. Incorporating sonar into a vehicle enables the driver of the vehicle to be notified of the distance between the vehicle and an obstacle, thereby enabling the driver of the vehicle to safely maneuver the vehicle before reaching the obstacle. This technology also enables the driver of the vehicle to avoid a collision with an unexpected obstacle.
In a vehicle equipped with sonar, the sonar equipment is in some cases installed in an opening that has been formed in a bumper of the vehicle beforehand. This bumper forms a portion of the exterior of the vehicle and thus affects the external appearance of the vehicle. Therefore, when forming holes in the bumper, it must be done without detracting from the appearance of the bumper.
Incidentally, Japanese Patent Application Publication No. 8-150428 (JP-A-8-150428) describes technology relating to press-forming that enables a through-hole having a tapered shape to be formed by a single press-forming operation.
A hole is formed in a bumper by pressing the bumper, which is mounted on a die, with a punch. However, in this case, burrs may form on the surface of the bumper. Incidentally, the burrs are formed by the bumper being deformed from the pressure of the punch on the bumper. When burrs form in the surface of the bumper, they may detract from the appearance of the bumper. In this case, the bumper may need to be reworked in order to improve its appearance. For example, the appearance of the bumper may need to be improved by manually deburring the bumper or attaching a seal member to hide the burrs on the bumper or the like.